Human milk is a unique biological fluid that has functional properties that appear to be as important if not more so than its nutritional properties. The overall goal of the project is to: 1) improve methods of isolating, characterizing and analyzing fat globules of human colostrum and milk; 2) develop a method of preparing milk and colostrum for microscopy such that the complete material can be viewed by light and electron microscopy; 3) using the above procedures and other available methods to enumerate and quantify the cytoplasmic cresents associated with fat globules in milk and colostrum; 4) evaluate factors which may influence their formation and devise a procedure for isolating the crescent material from them; 5) perfect a technique for isolating and purifying human fat globules based on centrifuging them from the milk or colostrum (up) through an overlying water or buffer layer; 6) employing the procedure in 4, develop or apply suitable methods for determining protein, phospholipid and cholesterol per gram of globules; and 7) isolate fat globules from colostrum and determine the pattern and concentration of carotenoids they contain.